Generally, when molten steel is poured from a tundish to a mould in continuous casting equipment, flux powder is sprinkled onto the surface of the molten steel in the mould, with the principal object of providing lubrication and heat retention of the molten steel.
Conventionally, flux powder is charged in such a way that the flux powder is placed above a mould, and the operator charges a suitable amount of flux powder while observing the surface of molten steel when pouring. Consequently, the working environment is adversely affected because of the high temperature and powdery dust generated from the molten steel, and the flux powder is supplied in an uneven distribution (i.e. uneven level).
There are presently utilized known apparatuses for supplying flux powder besides one (Japanese Utility Model Publication No. 48581/76) in which a screw conveyor is used, but these apparatuses have most important disadvantages in that a suitable amount of flux powder can hardly be sprinkled uniformly onto the surface of molten steel.
These days, there is used an apparatus (Japanese Utility Model Publication No. 39057/77) which uses a spring feeder, but it has less strength in view of its construction and thereby causes many troubles.
By the spring feeder is meant a feeder of known construction, in which a spring (coiled) is inserted, almost over the length, of a flexible hose provided beneath a hopper containing flux powder (material) and one end of said spring is directly connected to a motor. The flux powder proceeds by following the rotation of said spring which is rotated by means of the rotational, driving force of the motor, and then the flux powder is fed in said flexible hose to be supplied to a discharge port above a mould.
Further, Japanese Utility Model Publication No. 106410/77 proposes an automatic supply apparatus for flux powder, in which a supply pipe with an internally mounted screw is provided together on a stand and which is driven by means of a motor fixed at the rear of said supply pipe. Since the nozzle opening at the end of the screw makes a circular movement in this apparatus, however, flux powder cannot be sprinkled linearly and uniformly.
In addition, because of the rotary, circular movement affected by a gear it is impossible to change or regulate the moving range (stroke) of the nozzle opening, as necessary, to the width direction of the mould, and it is impossible to freely exchange the nozzle opening for sprinkling flux powder in proper amount and evenly in conformity with the size of the mould.
Thus, conventional apparatuses having spring feeder or screw feeder have fundamental, constructional faults or functional inconveniences and demerits so that at present operational requirements are not solved to satisfaction.
That is, the site of the pouring operation is always effected under the circumstances of high temperature and flying dust. Therefore, the constructional members become fragile and are unable to achieve the desired objects. Also, it has not been possible to sufficiently control the continuous, even feeding of flux powder in proper amount due to incomplete mechanism and operation.